JP2010283862A - Base station for managing neighboring state of cells and cell operation - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device which allow a simple and distributed method of determination of neighboring cells in a distributed wireless cellular network or in a wireless cellular network, wherein the number of or the location of base stations evolve by a significant amount. <P>SOLUTION: In order to determine if a first cell managed by a first base station is neighbor of a second cell managed by a second base station, the wireless cellular network includes a telecommunications network, enabling the transfer of information between the base stations. The first base station monitors the amount of information transferred between the first base station and the second base station through the telecommunications network and determines, if the second cell managed by the second base station is a neighbor of the first cell managed by the first base station according to the amount of monitored information transferred between the first base station and the second base station through the telecommunications network. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  In general, the invention relates to whether a first cell of a wireless cellular network managed by a first base station is adjacent to a second cell of a wireless cellular network managed by a second base station. It relates to the field of judgment.

  Current wireless cellular networks are based on a centralized architecture. A base station controller controls a plurality of base stations, and the base station is intended to cover a given cell. When an operator of a cellular radio mobile network wants to add a cell to the network, the operator typically performs the following operations. First, an operator installs a base station on the site and physically connects the base station to a base station controller that is responsible for the base station. The operator then configures the base station in the base station's operation domain such as the frequency, time slot, or code used by the base station controller for the base station operation. Configure the base station controller.

  In addition, the base station controller handles the handover procedure of the mobile terminal from the newly added cell to the existing neighbor cell or from the existing neighbor cell to the newly added cell, The mobile terminals that move around in the area that the mobile terminal is responsible for can be seamlessly continued while moving from one cell to another.

  To enable the handover procedure, the base station controller must know the neighbor situation between the newly added cell and the existing cell. Usually, such adjacency determination is defined according to radio network planning techniques.

  The radio network plan is conventionally determined by a simulation method. Prior to installing a base station at a given site, a cell that is a neighbor of this newly introduced cell is determined. Such simulation methods typically require information related to the propagation of radio waves in the vicinity of the cell, in addition to detailed knowledge of the type, position and steering of the antenna used to operate each cell. Is done.

  Such techniques are adapted for centralized wireless cellular networks or wireless cellular networks that do not change significantly over time. If the number of base stations that must be added is fairly important, or if one or several base stations need to be moved from one location to another, for maintenance purposes, or Such techniques are not efficient if some base stations are powered off periodically.

British Patent Application No. 2331892 (page 2, line 17 to page 3, line 13, page 13, line 20 to page 15, line 12) U.S. Pat.No. 5,864,764 (column 3, lines 24 to 38, column 5, lines 17 to 31, column 6, line 57 to column 7, line 10, column 59 to line 11, column 7, line 7, (Fig. 3)

  Accordingly, it is an object of the present invention to provide a method for enabling a simple distributed method for determining neighboring cells in a distributed wireless cellular network or a wireless cellular network in which the number or location of base stations varies greatly. Is to propose a device.

  The present invention also aims to propose a method and a device that make it possible to determine the cell operation domain of one or more cells managed by one base station in a distributed wireless cellular network.

To that end, the present invention is a method for determining whether a first cell managed by a first base station is adjacent to a second cell managed by a second base station. The two cells are cells of a wireless cellular network, the wireless cellular network comprising a telecommunications network enabling the transfer of information between base stations, the method being performed by a first base station Multiple steps
Monitoring the amount of information transferred between the first base station and the second base station through the telecommunications network;
According to the amount of monitored information transferred between the first base station and the second base station through the telecommunication network, the second cell managed by the second base station is transmitted by the first base station. Determining whether it is adjacent to the first cell to be managed.

The present invention is also a device for determining whether a first cell managed by a first base station is adjacent to a second cell managed by a second base station, the 2 One cell is a cell of a wireless cellular network, the wireless cellular network comprising a telecommunications network that enables the transfer of information between base stations, the device being included in a first base station, and
The device comprises means for monitoring the amount of information transferred between the first base station and the second base station over the telecommunications network;
According to the amount of monitored information transferred between the first base station and the second base station through the telecommunication network, the second cell managed by the second base station is transmitted by the first base station. Means for determining whether it is adjacent to the first cell to be managed.

  Accordingly, the determination of whether the second cell managed by the second base station is adjacent to the first cell managed by the first base station is distributed. It is no longer necessary to store the pre-calculated neighbor situation in any base station controller of the wireless cellular network in order to determine whether the base station cell is adjacent. By determining whether cells are adjacent according to the amount of information monitored, the data used for this determination can be obtained from real-world situations that are more reliable than simulation data.

  A mobile terminal that moves around the area served by a cell does not need to prepare for handover if the cell of another adjacent base station is not adjacent to the cell in which the mobile terminal is located, and is controlled by the base station There is no need to perform cell radio measurements.

  According to a particular feature, the amount of monitored information is the amount of information related to establishing a handover procedure of the mobile terminal in which the mobile terminal moves from the first cell to the second cell and vice versa. .

  Therefore, by monitoring the amount of information related to the handover procedure of a mobile terminal moving from the first cell to the second cell and vice versa, the data used for the neighbor cell decision is reliable. Become.

  According to a particular feature, the wireless cellular network further comprises a server linked to the telecommunication network, the first base station receiving information identifying at least one second base station in the telecommunication network from the server. Using the information received and identifying one second base station or each second base station in the telecommunications network, the first base station and one second base station or each second base station The amount of information that is established and monitored through the telecommunications network is the amount of information transferred over the established connection.

  Thus, the first base station knows each second base station and can communicate with each second base station. The first base station can further test whether each second base station cell is adjacent to the first cell.

  Further, the adjacency accuracy provided by the server is reduced compared to the adjacency accuracy normally stored in a conventional base station controller.

According to a particular feature, each of the base stations comprises at least one access port through which a connection is established, the first base station comprising:
Transfer each identifier of the access port of the first base station to the server;
Receiving from the server at least one identifier of one available access port of each second base station;
Establishing a connection with at least one second base station using the available access port of the first base station and the available access port of the at least one second base station.

  Therefore, when a plurality of second base stations are connected to the same first base station, different access ports of the first base station are used for connection with each second base station. . The signaling in each connection can be well separated from the signaling of other connections, and access collisions between the second base stations exchanging signaling with the first base station can be avoided.

  According to a particular feature, the first base station forwards the identifier of the access port used by the first base station for connection with the second base station to the second base station.

  Therefore, the second base station can also connect itself to the first base station.

  According to a particular feature, the first base station is connected to the first base station with an identifier of the access port used by the first base station for connection to the second base station. The access port identifier used by the second base station is transferred to the server.

  Thus, the server instructs the other first base station to use these access ports when another first base station attempts to connect to the first base station or the second base station. Can be avoided.

According to a particular feature, the first base station is
Check whether the amount of monitored information transferred over the connection between the first base station and the second base station is less than a predetermined threshold;
Release the connection with the second base station when the amount of monitored information transferred over the connection between the first base station and the second base station is less than a predetermined threshold ,
A message notifying that the access port of the first base station and the access port of the second base station used for the connection to be released is available is transferred to the server.

  Therefore, the access port can be used for further connection.

  According to a particular feature, the first base station receives information representing an operation domain of at least one second cell from the second base station, and information representing the operation domain of at least one second cell. To determine the operation domain of the first cell.

  Thus, no base station controller is required in the present wireless cellular network. Each base station can determine its own operation domain. Further, by determining its own operation domain from the operation domain of the neighboring base station cell, the base station avoids any possible collisions between the operation domains.

  According to a particular feature, the first base station forwards information relating to the location of the first base station to the server before receiving information identifying the second base station from the server in the telecommunication network. To do.

  Thus, the server knows the location of the first base station.

According to yet another aspect, the present invention provides a first cell managing first cell whether or not the first cell is adjacent to a second cell managed by at least a second base station. A method for enabling determination by a base station, wherein the two cells are cells of a wireless cellular network, wherein the wireless cellular network includes a server, a base station, and at least a first base station and a server. And a telecommunication network that enables the transfer of information between them. The server
Receiving information related to the location of the first base station from the first base station;
Determining at least a second base station located in the vicinity of the first base station according to information related to the location of the first base station;
Information identifying at least a second base station in the telecommunication network is transferred to the first base station.

The present invention also allows the first base station managing the first cell to determine whether the first cell is adjacent to at least the second cell managed by at least the second base station. The two cells are cells of a wireless cellular network, and the wireless cellular network enables transfer of information between base stations and at least between the first base station and the server. The present invention relates to a server including a telecommunications network. The server
Means for receiving information related to the location of the first base station from the first base station;
Means for determining at least a second base station located proximate to the first base station according to information related to the location of the first base station;
Means for transferring to the first base station information identifying at least a second base station in the telecommunications network.

  Accordingly, the determination of whether the second cell managed by the second base station is adjacent to the first cell managed by the first base station is distributed. A server that knows the location of a base station in a wireless cellular network can define a base station adjacent to the first base station. Two geographically adjacent base stations mean that a mobile terminal located in one cell may measure the radio conditions of the second cell that can trigger the handover procedure, This includes the possibility that cells managed by these two base stations may be adjacent to each other.

  Furthermore, the task of the first base station is simplified by transferring the identifier of the neighboring base station.

  The present invention determines in two steps whether two cells are adjacent. The first step is performed by the server to determine neighboring base stations based on a first criterion that is the location of the base station. The second step consists in determining neighboring cells of neighboring base stations based on a second criterion, which is performed by the base stations and is the amount of monitored information transferred between base stations.

  According to a particular feature, a plurality of second base stations are determined and information identifying at least each determined second base station is transferred to the first base station and determined at least in the telecommunication network The information for identifying each of the second base stations is an identifier of the second base station and at least one identifier of an available access port of the second base station.

  Thus, the server avoids notifying the first base station to connect to the second base station if there is no available access port left for connection with the second base station. Can do. The first base station may always establish such a direct connection if there is an available access port dedicated for the purpose of establishing a direct connection without contention with the second base station. it can.

  According to yet another aspect, the present invention is a computer program that can be loaded directly into a programmable device, and when the computer program is executed on the programmable device, implements the steps of the method according to the present invention. The present invention relates to a computer program including an instruction or a code part.

  Since the functions and advantages relating to the computer programs are the same as those set out above related to the method and device according to the invention, they will not be repeated here.

  The features of the present invention will become more apparent upon reading the following description of an example embodiment. The following description has been made with reference to the accompanying drawings.

1 represents the architecture of a wireless cellular network according to the invention. Fig. 2 is a diagram representing the architecture of a server according to the present invention. Fig. 2 is a diagram representing the architecture of a base station according to the present invention. Fig. 4 is an algorithm executed by a base station when the base station is installed in a wireless cellular network according to the present invention. Fig. 4 is an algorithm executed by a server when a base station is installed in a wireless cellular network according to the present invention. 3 is an algorithm executed by a base station adjacent to a base station installed in a wireless cellular network according to the present invention.

  FIG. 1 is a diagram representing the architecture of a wireless cellular network according to the present invention.

  In the wireless cellular network of FIG. 1, several base stations 10 a, 10 b, 10 c and 10 d are linked to each other through a telecommunications network 50. These base stations 10 a to 10 d access services provided by the server 20 through the same telecommunication network 50.

  Each base station 10 a to 10 d is responsible for at least one cell 15. In this cell 15, the mobile terminal 30 located in the cell 15 can detect a pilot signal through the base station 10 that manages the cell 15, and can establish or receive some communications.

  In FIG. 1, only one cell 15a, 15b, and 15d is shown for each of the base stations 10a, 10b, and 10d, but a more important number of cells are managed by the base station 10 in the present invention. I understand that.

  A cell 15 can be defined as a set of geographical locations, which is a given base station 10 that is included in that cell 15 among the pilot signals of other neighboring cells 15. A geographical location that provides the highest quality pilot signal received by the mobile terminal 30.

  For simplicity, the cells managed by the base station 10c are not shown in FIG.

  In FIG. 1, only four base stations 10a to 10d are shown, but it can be understood that a larger number of more important base stations 10 can be used in the present invention. Similarly, although only one server 20 is shown, it can be appreciated that a number of more important servers can be used with the present invention.

  The server 20 stores information about all base stations 10a to 10d linked to the telecommunications network 50. These pieces of information are information representing the geographical locations of the different base stations 10a to 10d and information representing the respective international base subscriber identifiers of the base stations 10. Using such information, the server 20 can determine which given base station 10 of the base stations 10 a-10 d is geographically adjacent to the given base station 10.

  The telecommunications network 50 is a dedicated wired network, a public network such as a public switched network, an IP-based network, a wireless network, or a combination of the networks listed above.

  The telecommunication network 50 connects the base station 10 and the server 20 to each other in accordance with the present invention, enabling the transfer of messages between the base stations 10 and the transfer of messages between each base station 10 and the server 20. .

  Each base station 10 is connected to the telecommunications network 50 through at least one link. Preferably, each base station 10 is connected to the telecommunications network 50 through at least two links.

  Such a link is more preferably a physical access port or a logical access port. The access port allows information to be transferred between the two base stations 10a and 10b.

  The base station 10a has two access ports indicated by P10a1 and P10a2, the base station 10b has two access ports indicated by P10b1 and P10b2, and the base station 10c is indicated by 2 indicated by P10c1 and P10c2. The base station 10d has two access ports indicated by P10d1 and P10d2.

  For simplicity, only two access ports are shown in FIG. 1 for each of the base stations 10a-10d, but it will be understood that a more important number of access ports are used in the present invention.

  The general principle of the present invention is that a wireless telecommunication network is constructed from interconnected base stations 10 and these base stations can handle a plurality of cells 15 individually. When a new base station 10, for example base station 10b, is added to the wireless telecommunication network, such base station 10b connects itself to the server 20 and further communication with other base stations 10 A list of access ports P10b1 and P10b2 used in the

  For such newly added base station 10b, the server 20 determines a large list of neighboring base stations 10 assumed to be adjacent to the base station 10b according to the first criterion. Such a first reference is based on a distance separating the base stations 10 as an example. More precisely, when a distance separating a base station 10 from another base station 10 is smaller than a predetermined distance, a base station 10 is adjacent to another base station 10. When two base stations 10 are adjacent, the cell 15 managed by each of the base stations 10 can be regarded as a potential adjacent cell.

  Such a list of neighboring base stations 10 is returned to the base station 10b along with the address of each neighboring base station 10 and at least one access port identifier.

  The server 20 transmits a list including the addresses and access port numbers of the adjacent base stations 10a and 10d according to the first reference to the base station 10b.

  The base station 10b then establishes some permanent physical or logical connection with its neighbor base stations 10a and 10d.

  The connection between the base stations 10a and 10b is shown as Co1 in FIG. 1 and is created through links P10a1 and P10b1.

  The connection between the base stations 10b and 10c is shown as Co2 in FIG. 1 and is created through links P10b2 and P10d2.

  As soon as the connection between the base stations 10 is ready, the base station 10b is related to the operation domain used by the neighboring cells involved by the neighboring base station 10 such as frequency, time slot, code, etc. Retrieve information.

  From this information, the base station 10b determines its own operation domain that the cell 15b can accept, and then starts to operate its own radio cell 15b in the selected operation domain. And 10d. The base stations 10a and 10d then add this new cell 15b to their respective broadcast neighbor cell lists and, if necessary, proceed to the handover procedure with the newly added cell 15b, The mobile terminal 30 serving each of the 10d cells 15a and 15d can measure the signal of the newly added cell 15b. On the side of the newly added cell 15b, the base station 10b starts broadcasting the neighbor cell list of the cell 15b in its own cell 15b for the same reason.

  After a given time, the base station 10b checks whether its neighboring base stations 10a and 10d cells 15a, 15d are adjacent to their cell 15b according to the second criterion. . This second standard is different from the first standard. Such a second criterion, as an example, was transferred through each of the connections Co1 and Co2 used to establish a handover between the cell 15b of the base station 10b and the potential neighboring cell 15a or 15d. Represents the amount of information.

  If the base station 10b determines that the amount of information regarding handover across cells 15a and 15b, as observed across the connection Co1, is marginal to the activity of the base station 10b, the given cell 15a Determines that it is no longer adjacent to its own cell 15b. In such a case, the base station 10b reconstructs the neighbor cell list broadcast in the cell 15b, and the mobile terminal 30 located in the cell 15b no longer takes measurements on the cell 15a to prepare for handover. Do not do it.

  Similarly, in such a case, the base station 10a can voluntarily decide to remove any cell 15b from any neighboring cell list of its own cell 15a.

  When the base station 10b determines that the activity of connection with a certain base station 10 is small relative to its own activity, the base station 10b starts a base station connection release procedure with one of the adjacent base stations 10a and 10d. In such a case, the base station 10b stops the connection with the base station 10. If the base station 10 is a base station 10d, the connection Co2 is released and the associated access port is used by both base stations 10b and 10d for further connections with some other base stations 10 It becomes possible. To that end, the released base station 10b informs the server 20 that its access port P10b2 is now available and that the access port P10b2 is no longer connected to the base station 10d via the access port P10d2. Notice.

  The neighbor cell lists of the cells of the base stations 10b and 10d are updated accordingly.

  Thereafter, the neighbor cell list converges to a limited number of neighbors.

  In the case of the handover procedure, the communication context of the mobile terminal 30 is exchanged between the base stations 10a and 10b via the connection Co1 and between the base stations 10b and 10d via the connection Co2.

  It has to be noted here that the general principle of the invention is disclosed in an example where each base station 10 manages one cell 15. When the base station 10 manages a plurality of cells 15, the same process is performed for each of the cells 15 managed by the base station 10.

  FIG. 2 is a diagram representing the architecture of a server according to the present invention.

  The server 20 has, for example, an architecture based on components interconnected by a bus 201 and a processor 200 controlled by a program as disclosed in FIG.

  The bus 201 links the processor 200 to a read only memory ROM 202, a random access memory RAM 203, a telecommunications network interface 206, and a database 204.

  The memory 203 includes variables and registers intended to contain program instructions related to the algorithm as disclosed in FIG.

  The processor 200 executes an algorithm as disclosed in FIG.

  The read-only memory 202 includes program instructions related to the algorithm as disclosed in FIG. These instructions are transferred to the random access memory 203 when the server 20 is powered on.

  Server 20 is connected to telecommunications network 50 through network interface 206. As an example, the network interface 206 is a DSL (Digital Subscriber Line) modem, an ISDN (Integrated Services Digital Network) interface, a PLC (Power Line Communication) interface, a wireless interface, or the like. Through such an interface, server 20 forwards information to base station 10 as disclosed with respect to FIG.

  The database 204 is all related to the base station 10, such as information representing the geographical location of the base station 10, each international base subscriber identifier of the base station 10, and the available access ports of the base station 10. Contains information.

  FIG. 3 is a diagram representing the architecture of a base station according to the present invention.

  The base station 10 has, for example, an architecture based on components interconnected by a bus 301 and a processor 300 controlled by a program as disclosed in FIGS. 4 and 6.

  The bus 301 links the processor 300 to a read only memory ROM 302, a random access memory RAM 303, a network interface 304, and a wireless interface 306.

  Memory 303 related variables, neighbor base station list, neighbor cell list of base station 10 cell 15, respective operation domains of neighbor cell 15, and algorithms as disclosed in FIGS. 4 and 6. Contains registers intended to contain program instructions.

  The processor 300 controls the operation of the network interface 304 and the wireless interface 306.

  The read only memory 302 includes program instructions related to the algorithm as disclosed in FIGS. These instructions are transferred to the random access memory 303 when the base station 10 is powered on.

  The base station 10 is connected to the telecommunications network 50 through a network interface 304. As an example, the network interface 304 is a DSL (Digital Subscriber Line) modem, an ISDN (Integrated Services Digital Network) interface, a PLC (Power Line Communication) interface, a wireless interface, or the like. Through such an interface, the base station 10 exchanges information with the server 20 and also exchanges information with the neighboring base station 10 that manages the potential neighboring cell 15.

  The network interface 304 includes several access ports. Each access port is used for a dedicated connection with one base station 10 that manages at least one neighboring cell 15. It has to be noted here that one common access port can be dedicated for negotiation with an unknown base station for a given access port that is used later for connection. Another specific access port can be dedicated for signaling with the server 20.

  The radio interface 306 enables communication with the mobile terminal 30 existing in the cell 15 of the base station 10. The radio interface 306 includes one radio antenna or a plurality of radio antennas, and each radio antenna serves a given cell 15 of the base station 10.

  FIG. 4 is an algorithm executed by a base station when the base station is installed in a wireless cellular network according to the present invention.

  Such an algorithm is, for example, when the base station 10 is installed and connected to the telecommunications network 50, or when the base station 10 is powered on, or when the base station 10 is separated from a certain location. Executed by the processor 300 of the base station 10.

  At step S400, the processor 300 acquires information representing the location of the base station 10. Such information is acquired from a person who installed the base station 10 through a man-machine interface (not shown in FIG. 3), or is included in or connected to the base station 10 by way of example and not limitation. Acquired through a global positioning system (GPS) device. The information indicating the location of the base station 10 is, for example and not limitation, the address of the building where the base station 10 is located, the telephone number assigned to the telephone line in the building where the base station 10 is located, or the base station Any other network address that makes it possible to retrieve the address of the building where 10b is located, or the GPS coordinates of the base station 10, i.e. the latitude, longitude, and altitude of the location of the base station 10.

  Further, the information indicating the location of the base station 10 can be the amplitude of the signal and the identifier of the base station 10 included in the signal. These signals are transmitted by some base stations 10 within each cell 15 of the base station 10 and received by the base station 10 or a device connected to the base station 10.

  At step S401, the processor 300 commands the transfer of the registration message to the server 20. This registration message includes information representing the location of the base station 10 acquired in advance, the telecommunications network address of the base station 10 and the identifier of each access port of the base station 10. As an example, if the base station 10 is the base station 10b, the processor 300 commands the transfer of the network address of the base station 10b and the identifiers of the access ports P10b1 and P10b2 of the base station 10b. In a variant of realization, the base station 10b only uses the identifier of the access port P10b1 or P10b2 that has to be used to negotiate further connections with some other base station 10 or to initialize further connections. Forward. In another variant of realization, the base station 10b also forwards the identifier of one access port P10b1 or P10b2 dedicated to communication with the server 20.

  At next step S402, the processor 300 receives a response message from the server 20 via the telecommunication network 50. This response message includes a list of neighboring base stations 10 determined by the server 20 according to the first criterion. This list of neighboring base stations 10 includes the addresses in the telecommunication network 50 of the base stations 10 that are adjacent to the base station 10b according to the first criterion. According to the example of FIG. 1, this list includes the addresses of the base stations 10a and 10d.

  More precisely, the list of neighboring base stations 10 also includes an identifier of at least one access port available for future connections for each of the base stations 10a and 10d that are neighbors of the base station 10b.

  At next step S403, the processor 300 establishes a connection with at least a part of the base stations 10 included in the list of neighboring base stations.

  More precisely, if the number of available access ports of the base station 10b is less than the number of base stations 10 included in the list of neighboring base stations, the processor 300 determines that the neighboring base station 10 of the base station 10b. A connection with the subset is established, and the remaining portion is stored in the RAM memory 303.

  A connection between the two base stations 10 through the telecommunications network 50 is established by reserving one access port for each base station 10 and through which a permanent signaling logic connection is established between the two base stations 10 Is established. Such a reservation of access ports can in one variant be made during the negotiation phase through a common access port dedicated to access port negotiation. Preferably, even if two base stations 10 may be associated with an adjacency state between three or more of the cell 15 of the base stations, there is at most one connection between the two base stations 10. Not established.

  By way of example and not limitation, the logical connection can be compatible with TCP (Transmission Control Protocol) protocol or UDP (User Datagram Protocol) protocol used over IP signaling.

  Each base station 10 assigns a unique identifier to each connection. Such an identifier is an identifier of an access port or an access port number. Further, the combination of the access port number and the IP address of the base station 10 forms a unique socket. The IP address is used to identify the base station 10, and the access port number identifies the connection itself.

  Therefore, when the base station 10b establishes a bidirectional signaling connection with another base station 10, for example, the base station 10a, the base station 10b sends its message to its own IP address and the IP address of the base station 10a. The base station 10b transmits together with the identifier of the access port reserved for the connection and the identifier of the access port that is still available in the base station 10a. Similarly, the base station 10a addresses the base station 10b with the IP address of the base station 10b and the access port identifier received from the base station 10b.

  In another implementation mode of the invention, all base stations 10 use the same single access port fixed for the purpose of common signaling between the base stations 10. The signal exchanged between the base stations 10 by the access port carries the identification information of the originating base station 10, but later a connection is established through the negotiated access port.

  Thereafter, a first connection indicated by Co1 is established between the base station 10b and the base station 10a through the access ports P10b1 and P10a1 of these base stations. Further, a second connection indicated by Co2 is established between the base station 10b and the base station 10d through the access ports P10b2 and P10d2 of the base stations.

  At the same step, the processor 300 forwards the message to the server 20 to inform the server 20 that the access port for each successful connection is not currently available.

  At step S404, through each established connection Co1 and Co2, the processor 300 is managed by the list of cells 15a and 15d managed by the neighboring base stations 10a and 10d of the base station 10b and by the neighboring base stations 10a and 10d. The operation domains of the cells 15a and 15d are acquired and stored in the RAM memory 303.

  The operation domain of the cell 15 managed by the base station 10 includes, by way of example and not limitation, the frequency used by the base station 10 in the cell 15 of the base station 10 and / or the base station in the cell 15 of the base station 10. 10 and / or codes used by the base station 10 in the cell 15 of the base station 10 are included.

  Each adjacent base station 10 transfers the operation domain of its cell 15 through the established connection with the base station 10b.

  At step S405, the processor 300 determines the operation domain of the cell 15b of the base station 10b.

  For this purpose, the processor 300 uses the occurrence table (occurrence table) of the operation domain received in step S404 and stored in the RAM memory 303 in the cell 15 of the adjacent base station 10 stored in the RAM memory 303 in step S404. of usage).

  The processor 300 selects an operation domain from among the operation domains having the smallest number of appearances observed in the cell 15 of the adjacent base station 10 for the cell 15b. If the base station 10b controls more than one cell 15b, this table also includes the operation domain of the cell 15b of the base station 10b. Each time an operation domain is selected for one cell 15b, the operation domain usage table is updated. Then, the operation domain of the subsequent cell 15b is selected from among the operation domains having the smallest number of occurrences and not yet selected for the other cell 15b.

  Preferably, for the cell 15b of the base station 10b, the processor 300 selects an operation domain from among the operation domains having the smallest number of appearances observed only in the cell 15 of the adjacent base station 10 of the base station 10b adjacent to the cell 15b. Select.

  In yet another preferred embodiment, the operation domain selection probability of the neighboring cell 15a of the cell 15b is the attenuation function of the monitoring information that quantifies the neighboring relationship between the cell 15a and the cell 15b collected in step S407. (Decaying function).

  At next step S406, the processor 300 returns the operation domain of the cell 15b to its neighboring base stations 10a and 10d through each connection Co1 and Co2, and the neighboring base stations 10a and 10d Allows you to maintain a usage number table.

  At next step S407, the processor 300 activates monitoring of information transferred through the connections Co1 and Co2 established at step S403.

  The information to be monitored is, for example, a message transferred to the adjacent base station 10a and / or a message received from the adjacent base station 10a related to the handover procedure of the mobile terminal 30 included in each cell 15. .

  The handover procedure is performed when the mobile terminal 30 is communicating with another telecommunication device through a given base station 10b in the first cell 15b and moves to the cell 15a of the neighboring base station 10a. During the handover procedure, a given base station 10b must stop serving the mobile terminal 30, and the neighboring base station 10a must start serving the mobile terminal 30, Thus, communication can be continued. During the soft handover procedure, the neighboring base station 10a must start serving the mobile terminal 30, while a given base station 10b continues to serve the mobile terminal 30, thereby providing macro diversity and Communication over multiple cells can be continued simultaneously.

  If the handover procedure is actuated by the mobile terminal 30, it is piloted from the cell 15a with a power strength higher than that of the pilot signal of the cell 15b while the mobile terminal 30 is still located in the first cell 15b. This means that a signal is received, which means that the cell 15a is a valid neighboring cell of the cell 15b of the base station 10b. When a handover procedure between two base stations 10 is realized, several specific signaling messages are exchanged between the two base stations 10.

  Using these information over a number of consecutive handover procedures involving two or more mobile terminals 30 or parallel handover procedures, the base station 10b can determine which of its neighboring cells 15 has its own cell 15b. It is possible to determine whether each is a neighboring cell.

  By way of example and not limitation, messages related to handover procedures from cell 15b to cell 15a managed by base station 10a / handover procedures from cell 15a to cell 15b managed by base station 10a are forwarded through connection Co1. Each time, processor 300 increments a counter associated with the adjacency relationship between cell 15b and cell 15a of base station 10a. Each time a message related to the handover procedure from the cell 15b to the cell 15d managed by the base station 10d / the handover procedure from the cell 15d to the cell 15b managed by the base station 10d is transferred through the connection Co2, the processor 300 Increments a counter associated with the adjacency between cell 15b of base station 10a and cell 15d of base station 10d.

  As another example, each time a message related to a handover procedure is transferred through connection Co1, the processor 300 increments a counter associated with the connection Co1. Each time a message related to the handover procedure is transferred through connection Co2, the processor 300 increments a counter associated with connection Co2.

  At next step S408, the processor 300 determines whether or not the cell 15 of its neighboring base station 10 has to check whether it is a neighboring cell of its cell according to the second criterion.

  By way of example and not limitation, a processor after a predetermined time of operation of base station 10b and / or periodically and / or when the amount of information transferred over connections Co1 and Co2 reaches a predetermined amount 300 determines that the cell 15 of its neighbor base station 10 has to check whether it is a neighbor of its own cell according to the second criterion.

  If the processor 300 has to check if the cell 15 of his neighbor base station 10 is a neighbor cell of his cell according to the second criterion, the processor 300 moves to step S409. Otherwise, the processor 300 moves to step S420.

  At step S420, the processor 300 checks whether or not the neighboring base station 10 has received a message from the neighboring base station 10 notifying itself that the neighboring base station 10 will suppress connection with itself.

  If no message is received, the processor 300 returns to step S408.

  If such a message is received, the processor 300 moves to step S421.

  At step S421, the processor 300 deletes the base station 10 that transmitted the message from the list of neighboring base stations. Further, the processor 300 deletes the one or more cells 15 handled by the base station 10 that transmitted the message from the neighboring cell list of the cell 15b handled by the processor 300, and the one or more cells 15 handled by the base station 10 Delete the operation domain from the operation domain usage table.

  At next step S422, the processor 300 confirms that the connection between the base station 10b and the other base station 10 which sent the message at step S408 has been disconnected and that the access port of the connection is further accessed. A message notifying the server 20 that it is currently available is transferred to the server 20.

  The processor 300 then returns to step S405 to define a new operation domain for its cell 15. It is interesting to make a new determination of the operation domain of the processor 300 cell as long as the operation domain of the cell is defined according to the operation domain of the neighboring cell and / or according to the monitored information collected in step S407. (Interesting).

  Here, if the processor 300 has established a connection with the subset of its own neighboring base station 10 in step S403, the processor 300 moves to step S403 and stores the base station 10 stored in the RAM memory 303. It should be noted that the remaining base station 10 is considered and the present algorithm is continued.

  At step S409, the processor 300 considers a first connection with one of its possible neighboring base stations 10. As an example, the processor 300 considers the connection Co1.

  At next step S410, the processor 300 checks if there is any activity on the connection and updates the cell neighbor status according to the monitored information.

  To that end, in one mode of realization of the present invention, processor 300 reads the value of the counter associated with the connection being processed. If the counter value is greater than the predetermined threshold value, the processor 300 determines that there has been some activity in the connection and moves to step S411. Otherwise, the processor 300 moves to step S413.

  Here, in a variant of realization, the processor 300 calculates the sum of the respective values of the counters associated with the connections Co1 and Co2, and divides the value of the counter associated with the connection being processed by the calculated sum. Note that it is compared to a predetermined threshold.

  In another implementation mode of the invention, processor 300 reads the value of a counter associated with the adjacency relationship between each cell 15b of base station 10b and each cell 15a of remote base station 10a. If the value of the counter is greater than the first predetermined threshold and the cell 15a is not yet part of the cell 15b neighbor cell list, the cell 15a is added to the cell 15b neighbor cell list. Is done. When the counter value is smaller than the second predetermined threshold and the cell 15a is a part of the adjacent cell list of the cell 15b, the cell 15a is deleted from the adjacent cell list of the cell 15b. The When this is done for all cells 15b and 15a, the processor 300 informs the wireless interface 306 to start broadcasting the updated neighbor cell list for cell 15b.

  Here, in a variant of realization, the processor 300 calculates the sum of each value of the counter and divides each value of the counter associated with the connection being processed by the calculated sum, Note that it is compared to a threshold.

  At step S411, the processor 300 checks if there are other connections whose activity is not checked.

  If there is at least one connection for which activity is not checked, the processor 300 moves to step S412 to consider another connection and returns to step S410.

  If there are no more connections whose activity has not been checked, the processor 300 returns to step S408.

  At step S413, the processor 300 deletes the base station 10 to which it is connected through the connection being processed from the list of neighboring base stations. Further, the processor 300 deletes the cell handled by the base station 10 to which the processor 300 is connected through the connection being processed from the neighboring cell list of the cell 15 handled by the processor 300, and determines the operation domain of the cell handled by the base station 10 as follows: Delete from the operation domain usage table.

  As long as the amount of handover between the cells of the two base stations is limited or zero, it will cause each cell 15 of those base stations 10 to This means that it cannot be considered adjacent according to the criterion of 2.

  At next step S414, the processor 300 transmits a message notifying the base station 10 that the connection is suppressed to the base station 10 to which the processor 300 is linked through the connection being processed, and the access port of the connection To release.

  At next step S415, the processor 300 transfers to the server 20 a message notifying the server 20 that the access port for that connection is currently available. Preferably, the processor 300 informs the server that the access port of the neighboring base station 10 used for the connection is now available.

  The processor 300 then returns to step S405 to define a new operation domain for its cell 15.

  Here, if the processor 300 has established a connection with a subset of possible neighboring base stations 10 in step S403, the processor 300 moves to step S403 and stores it in the RAM memory 303. It should be noted that the remaining base stations 10 are considered and that this algorithm is executed in the same manner as already described.

  FIG. 5 is an algorithm executed by a server when a base station is installed in a wireless cellular network according to the present invention.

  This algorithm is executed by the processor 200 of the server 20.

  At step S500, the processor 200 checks if a message is received from the network interface 206. As long as no message is received, the processor 200 executes the loop constituted by step S500.

  When a message is received from the network interface 206, the processor 200 stores the content of the message in the RAM memory 203, and moves to step S503.

  At step S503, the processor 200 checks if the base station 10 that sent the message has already accessed the server 20. To that end, the processor 200 checks if a list of neighboring base stations has been created for that base station 10 or if the database 204 contains a list of available access ports for that base station 10.

  If the base station 10 that transmitted the message has already accessed the server 20, the processor 200 moves to step S504. Otherwise, the processor 200 moves to step S507.

  At step S507, the processor 200 determines the neighboring base station 10 of the base station 10 that transmitted the message according to some first criterion.

  This first criterion is preferably the distance between the geographical locations of the base stations.

  From the information representing the geographical location of the base station 10 included in the received message stored in the RAM 203 in step S500, the processor 200 consults the database 204 to determine a predetermined distance criterion or a given number of neighbors. A set of base stations 10 proximate to the location is determined with a distance criterion chosen to find the base station 10.

  If the information representing the location of the base station 10 that transmitted the message is the address of the building where the base station 10 is located, the processor 200 determines the latitude, longitude, and altitude of the base station 10 from the address, A set of base stations 10 proximate to the location is determined.

  If the information representing the location of the base station 10 that sent the message is a telephone number assigned to a telephone line in the building in which the base station 10 is located, the processor 200 determines an address from the telephone number and then Then, the latitude, longitude, and altitude of the base station 10b are obtained, and a set of base stations 10 close to the location is determined.

  If the information representing the location of the base station 10 that sent the message is the GPS coordinates of that base station 10, ie, the latitude, longitude, and altitude of the location of the base station 10, the processor 200 indicates that the base station is in proximity to that location. Ten sets are determined.

  If the information representing the location of the base station 10 is the amplitude and identifier of the signal measured by the base station 10 that sent the message, the processor 200 determines from the identified signal the latitude of that base station 10, The longitude and altitude estimates are obtained, and a set of base stations 10 adjacent to the estimated location is determined.

  At next step S508, the processor 200 retrieves from the database 204 the address and at least one available access port identifier in the telecommunication network 50 for each base station 10 close to the base station 10 that sent the message. . The processor 200 then selects the geographic location of the base station 10 that was included in the received message, a list of determined neighboring base stations having the address of the neighboring base station 10, and each of the determined lists. Information representing the selected available access port of the base station 10 is added to the database 204. At next step S509, the processor 200 commands the transfer of a response message including a list of neighboring base stations 10 over the telecommunication network 50 to the base station 10 which sent the message.

  The list of adjacent base stations 10 includes the address of the base station 10 that transmitted the message, the address of each base station 10 that is close to the base station 10 that transmitted the message, and each base station that is adjacent to the base station 10 that transmitted the message. And 10 available access port identifiers.

  When the message is transferred, the processor 200 returns to step S500 and waits for the reception of a new message to be processed.

  If at step S503, the processor 20 determines that the base station 10 that transmitted the message has already accessed the server 20, the processor 200 moves to step S504.

  At that step, the processor 200 checks if the received message stored in the RAM 203 at step S500 represents the availability status of the access port of the base station 10. Such a message is similar to the message transferred in step S415 or S422 of the algorithm of FIG.

  If the received message represents the availability status of the access port of the base station 10, the processor 200 moves to step S505 and in the database 204 the access port in the list of access ports of the base station 10 that sent the message. Update status. This update is either by marking the access port as available if the availability status indicates that the access port is available, or using the access port is unavailable This is done by marking the access port as unavailable when the possible status indicates. If the access port is marked as unavailable, the processor 200 indicates that the base station 10 connected through the link to the base station that sent the message is the neighbor base station of the base station 10 that sent the message. Remove from the list.

  The processor 200 returns to step S500 and waits for the reception of a new message to be processed.

  If the received message does not represent the availability status of the access port of the base station 10, the processor 200 moves to step S507 already described and continues processing the message.

  FIG. 6 is an algorithm executed by a base station adjacent to a base station installed in a wireless cellular network according to the present invention.

  At step S600, by way of example, the processor 300 of the base station 10a checks whether a message has been received from the network interface 304. As long as no message is received, the processor 300 executes the loop constituted by step S600.

  If a message is received from the network interface 304, for example from the base station 10b, the processor 300 stores the message in the RAM 203 and moves to step S603.

  At step S603, the processor 300 checks if the base station 10 that sent the message is known by the processor 300. To that end, the processor 300 checks if the message has been received from an already established connection.

  If the base station 10 that transmitted the message is known, the processor 300 moves to step S606. Otherwise, the processor 300 moves to step S604.

  At step S604, the processor 300 moves to connection establishment in response to the connection establishment as disclosed at step S403 of FIG.

  In the same step, in a variant of realization, the processor 300 transfers a message to the server 20 notifying the server 20 that the access port for that connection is currently unavailable.

  At next step S605, the processor 300 transfers the operation domain of its cell 15 to the base station 10 which transmitted the message. Next, the processor 300 returns to step S600.

  At step S606, the processor 300 checks if the received message is a message notifying the base station 10 that the connection between the base station 10 and the base station 10 that transmitted the message has been released.

  If the message is not a connection release message, the message stored in RAM 203 in step S600 includes the operation domain of one or more cells of base station 10 that transmitted the message. Next, the processor 300 moves to step S607 and updates the number-of-appearances table of usage of the operation domain of the cell 15 of its neighbor base station 10.

  After that, the processor 300 moves to step S611 disclosed later.

  If the message is a connection release message, the processor 300 moves to step S608.

  At step S608, the processor 300 deletes the base station 10 that transmitted the message from the list of neighboring base stations, deletes the cell that the base station 10 that transmitted the message is responsible for from the appearance number table of use of the operation domain, The operation domain of the cell of the base station 10 is deleted from the operation domain use table, and the cell is deleted from the neighbor cell list. For each cell served by the base station 10, the processor 300 instructs the wireless interface 306 to start broadcasting the updated neighbor cell list.

  At step S609, the processor 300 releases the connection with the base station 10 that transmitted the message.

  In a variation of realization, the processor 300 transfers to the server 20 a message informing the server 20 that the access port used for the connection to be released is now available at step S610. The processor 300 moves then to step S611.

  At next step S611, the processor 300 determines the operation domain of its own cell 15 using the table of use of the changed operation domain.

  The processor 300 selects an operation domain for the cell 15 from the operation domains having the smallest number of appearances observed in the cell of the adjacent base station 10. If the base station 10 controls more than one cell, this table also includes all operational domains of its own cell 15. Each time an operation domain is selected for one cell 15, the operation domain usage table is updated. Next, the operation domain of the subsequent cell 15 is selected from among the operation domains that have the smallest number of occurrences and have not yet been selected for the other cells 15.

  In a preferred embodiment, processor 300 minimizes the number of occurrences observed for cell 15 of its base station 10 only in cells 15 of neighboring base stations 10 adjacent to cell 15 of its base station 10. The operation domain is selected from the operation domains.

  At next step S612, the processor 300 transfers the determined operation domain of its cell 15 to all its neighboring base stations 10 through each connection. Next, the processor 300 returns to step S600.

  Naturally, many modifications can be made to the embodiments of the invention described above without departing from the scope of the present invention.

Claims (1)

A base station that manages cell adjacency state and cell operation,
The cell is a cell of a wireless cellular network;
The wireless cellular network comprises a telecommunications network that enables transfer of information between the base station and a second base station;
The wireless cellular network comprises a server linked to the telecommunications network in a base station,
The base station
As used to establish a connection between the base station and the second base station, such that information identifying the second base station in the telecommunications network is received from the server at the base station A configured first unit;
A second unit configured to establish a connection between the base station and the second base station through the telecommunications network;
A third unit configured to receive at the base station information representing an operation domain of a second cell managed by the second base station;
A fourth unit configured to determine an operation domain of the first cell managed by the base station according to the information representative of the operation domain of the second cell at the base station;
And a fifth unit configured to release the connection with the second base station.

Images